Presence of different networks (network addresses are different) in a same organization is not a rare situation. Hosts in different networks are usually capable of communicating with each other via a router. However, in some cases, intercommunication between the different networks is desired to be limited even in the same organization. For example, in a public office or a hospital, there are two different types of networks including: a first network through which information that should be kept secret flows, such as private information; and a second network for an Office Automation (OA) system through which information whose secrecy is not as high as the private information flows, such as sales data or personnel data. Also in private-sector companies, owing to mergers-and-acquisitions (M&A), in some cases, members from originally different enterprises work on the same floor and use different networks (e.g., an enterprise A uses the first network and an enterprise B uses the second network).
In the above cases, the information flowing through the first network should not flow into the second network, and the information flowing through the second network should not flow into the first network.
Additionally, input and output apparatuses such as printers are often used in business activities in public offices, hospitals, and private-sector companies. However, in a case where input and output apparatuses are provided for the respective networks, large burdens are applied on the organizations and installation spaces are also needed for the number of input and output apparatuses. Hence, there is a demand for reducing the number of input and output apparatuses by using a common input and output apparatus.
In order to meet such a demand, an input and output apparatus with a plurality of network interfaces is known (e.g., see Patent Document 1). Patent Document 1 discloses an image-forming apparatus with a plurality of network interfaces respectively coupled with a plurality of network segments. The image-forming apparatus controls communication between each of the plurality of network interfaces and another apparatus in accordance with communication propriety setting means that are set for the image-forming apparatus with respect to proprieties for communicating between the plurality of network interfaces and other apparatuses.